R. N. Adhikari , M. S. Rama Mohan Rao , A. K. Singh , K. K. Reddy

Abstract

Vegetative measures for soil & water conservation are preferred due to their efficacy and cost effectiveness. A study conducted during 1996-2000 in black soil semi-arid region showed that among the commonly occurring grasses, Cenchrus ciliaris, Dichanthium annulatum and Cymbopogon martini were most effective in reducing surface runoff which ranged from 9 to 12%, while sediment loss varied from 500 - 1000 kg/ha and was below permissible limits of 5 t/ha/year. Cymbopogon has drought resistance and capability to withstand limited grazing. It also gives comparatively more (1.7 to 2.4 times) biomass production with aromatic uses. Thus, from a holistic perspective Cymbopogon is recommended for conservation and production. By artificial seeding on large scale, Cymbopogon, Ciliaris and Dichanthium can replace the Sehima species which has currently failed to survive due to changed environment.

Keywords

Grass Species, Run-off, Soil Loss, Semi-arid, Black Soil

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R. N. Adhlkari , M. S. R. Rao , V. Selvi , S. K. N. Math , V. Husenappa , K. K. Reddy

Abstract

The 'C' value obtained from standard table by using the rational formula Q = ClA/S60 for arriving at discharges appears to be high under semi-arid conditions of,India, since in many years a high discharge is never observed. 'C' value computed from runoff data recorded under different types of vegetation cover under field conditions are presented in this paper. It is found that the 'C' value is 40 to 60% less than the value presented in the standard table. The value of modified 'C' were tested in a independent watershed in aimilar agroclimatic conditions. By adopting these values it is possible to reduce the section of a structure and thereby the cost. This was tested and it was observed that structures using the modified 'C' values performed satisfactorily. A sample calculation is also shown.

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